The present invention relates generally to molded articles which may be blow molded such as a blow-molded ladder or a blow-molded staircase for a swimming pool.
Swimming pool ladders or staircases and various other articles have been made from a plastic material by a process known as “blow-molding,” as exemplified in commonly assigned U.S. Pat. No. 4,023,647 to Confer, commonly assigned U.S. Pat. No. 4,067,614 to Confer et al, and U.S. Pat. No. 4,166,833 to Schurman, all of which patents are hereby incorporated herein by reference. In the process of blow molding, a hollow thin-walled structure is formed having an exterior surface separated from an interior surface by the thin wall, and the hollow structure contains a fluid, in most cases air and/or water.
Pool Ladders with Vandal Guards
By way of background, swimming pool ladders of an A-frame type are positioned straddling a pool wall with the pool side having a ladder for entering and leaving the water (a.k.a., in-pool ladder) and an outside ladder for climbing over the outside of the pool wall (a.k.a., staircase ladder). In the past certain ladders of the foregoing type had relatively unwieldy structures for placing the outside ladder in an inaccessible position so as to prevent unauthorized entry into the pool. Also, insofar as known, ladders of the foregoing type, when disassembled, were not of a size which would fit into a box which was within the dimensions acceptable to commercial shippers. Other types of pool ladders were relatively complicated and difficult to assemble.
In U.S. Pat. No. 6,880,674; St-Hilaire wrote, “A door ladder assembly for use with the [sic] an above ground swimming pool, the assembly comprising a ladder having a plurality of steps, a door with a first side hingedly connected to one side of the ladder and arranged to hingedly move between open and closed positions, a handle being located at the top portion of the door, and a door lock to lock the door in a closed position, the door being provided with a lock operator to unlock the lock, the lock operator being located proximate the handle. The arrangement provides for easy access for an adult, while preventing a child from having access to the unlocking mechanism.” A prior version of a door gate for a pool ladder was disclosed in U.S. Pat. No. 3,225,863 to Ludlow and U.S. Pat. No. 3,968,857 to Bryan. Each of these prior pool ladder barriers are doors that swing on a hinge and are positioned over the A-frame ladder's staircase ladder. These barriers are variations of conventional vandal guards used in other industries.
An alternative vandal guard is disclosed in U.S. Pat. No. 4,579,197 to Spurling. Spurling wrote, “A ladder shield for use in preventing toddlers and the like from climbing the steps of a ladder, such as an above-ground swimming pool ladder, when the ladder or the device to which the ladder is coupled is unattended is disclosed. The ladder shield comprises a rigid yet slightly flexible shell of plastic which is sized and shaped to fit around the front and sides of the ladder so as to block access to the steps on the ladder. The ladder shield is removably secured to the ladder by a removable locking bar which when inserted extends through a pair of holes in the side walls of the shield. The locking bar is secured in place by a lock. When not being used to prevent access to the steps of the ladder, the ladder shield may be used as a mini-foot wash.
Ladders with a Tambour
A tambour device is defined at www.dictionary.com as “a flexible shutter used . . . in place of a door, composed of a number of closely set wood strips attached to a piece of cloth, the whole sliding in grooves along the sides or at the top and bottom.” Applicant conducted a search to determine if any ladder was associated with a tambour device. The closest reference, not a relevant reference, was U.S. Pat. No. 5,046,582 to Albrecht for a foldable ladder combination with truck cargo carrier. Albrecht wrote, “Commercial truckers frequently have situations arise where they require personal access to the elevated bed of the truck's cargo carrier. The cargo carrier may be mounted on the truck frame itself as in the case of a so-called bob-tail truck; or, the cargo carrier may be a trailer pulled by a truck tractor. In either case, the conventional truck cargo carrier includes an elongated approximately horizontal cargo bed elevated about four to five feet above ground level, and an elongated structural cargo enclosure extending upwardly from, and substantially covering the cargo bed. The cargo bed has a rear end from which cargo is loaded into and unloaded from the cargo carrier, and the structural cargo enclosure has at its rear end right and left side edges in the form of vertical posts extending upward from adjacent the rear end of the cargo bed, and typically has either a single “roll-up” tambour rear door which is engaged in slots disposed at the inboard lateral faces of the posts, or has a pair of swinging doors hinged to such vertical posts, for opening and closing the rear end of the structural cargo enclosure to provide loading and unloading rear access to the structural cargo enclosure and cargo bed.”